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GWMAW writes "NASA Astronauts will conduct a spacewalk on Thursday to repair part of the cooling system of the International Space Station. The cooling system is essential for maintaining the temperature inside the station. There are two 'loops' in the system, one that uses water and draws heat from the inside of the station, and one uses ammonia and dumps the heat into space. Ammonia is used because it freezes at a much lower temperature than water. On Saturday the pump that controls the flow of ammonia through the system shut down."

I'm sure you're just joking, but a lot of people have this misconception that space is cold.

The few particles floating around out there (background radiation included) is very cold yes, only a few degrees K. However, these particles are few and far between, and the actual vacuum of space has no temperature at all (although I'm not sure how to factor in virtual particles into this).

I believe that I read somewhere that floating unshielded through space, you are more likely to die from overheating, since you c

Without thermal controls, the temperature of the orbiting Space Station's Sun-facing side would soar to 250 degrees F (121 C), while thermometers on the dark side would plunge to minus 250 degrees F (-157 C). There might be a comfortable spot somewhere in the middle of the Station, but searching for it wouldn't be much fun!

Without thermal controls, the temperature of the orbiting Space Station's Sun-facing side would soar to 250 degrees F (121 C), while thermometers on the dark side would plunge to minus 250 degrees F (-157 C). There might be a comfortable spot somewhere in the middle of the Station, but searching for it wouldn't be much fun!

Oh come off it GP is not trolling. Temperature is always a matter of perspective, even in the room where I am now. If your spacecraft decompressed you would feel cold because of adiabatic expansion. Stand or float in the sun and you will feel warm, but radiation would still be cooling you.

Dear troller troll...You cannot loose heat in the vacuum. So all your heat is stored inside the space suit and not going anywhere. So yes, you can only overheat.In a mostly metallic structure, the hot side will irradiate the heat to all its body. So if not isolated, ALL ISS will be at +/- 121C.The space is cold, but you cannot feel it, because there are (almost) no heat transference.But if you touch, for example, an asteroid, all you heat will be quickly absorbed, and you will freeze to dead.

Maybe you cannot lose hear through convection but, in space, you can certainly loose heat by radiation. Deep space background is around 3K and a deep space radiative cooler is a very good and efficient way to cool something in space.

You cannot do any thermal analysis of an object in space without taking the radiative part into account.

Only matter has a temperature. Radiation has not, although absorbtion of radiation can cause an elevation in temperature of matter and matter can radiate heat and cool down that way.
An uninsulated space suit in a vacuum wouldn't feel very cold on the inside as long as the suit doesn't touch anything on the outside.

Without knowing the exact heat balances in play there, I'll take a stab at it. In a vacuum (assuming no out-gassing or other mass exchanges) there is only one way to change temperature -- absorb electromagnetic radiation (visible light, infrared, microwaves, etc.) to heat up and emit similar radiation to cool down. In the case of Apollo 13, the spacecraft absorbed solar radiation, although being painted white and bright aluminum it must not have been an efficient absorber. And it emitted radiation, peak

An uninsulated space suit in a vacuum wouldn't feel very cold on the inside as long as the suit doesn't touch anything on the outside.

What were the physics involved in the Apollo 13 mission when they were getting very cold after turning off the heaters in the spacecraft, using the LEM as a lifeboat?

When it comes to using power, it is easier to heat something than to cool it. The apollo spacecraft was designed to be passively cool in the sense that it reflected enough of the sunlight striking it to need as small amount of heating from batteries to stay warm. If it had absorbed more heat from the sun it would have required active cooling which is very expensive in energy terms.

I know this is a kdawson story and all, but what is there really to discuss here? Okay, so a part in space broken down and will be repaired. Seems like a pretty routine thing to me. I can understand if this were some unorthodox procedure or novel technology that had never been tried before, but that doesn't appear to be the case here.

Back on topic: um... good luck guys!

That's exactly what I thought. There was a story that it was broken, no shit they're gonna fix it!

Typical Slashdot, a bit behind. This is the press release they sent out on Tuesday.

Aug. 03, 2010

Stephanie SchierholzHeadquarters, Washington

James HartsfieldJohnson Space Center, Houston

MEDIA ADVISORY: M10-107

NASA MOVES SPACE STATION REPAIR SPACEWALK TO FRIDAY, SETS BRIEFINGS

HOUSTON -- The first of two spacewalks by NASA astronauts to replace afailed ammonia pump on the International Space Station has beendelayed by 24 hours to Friday, Aug. 6. A second spacewalk is plannedfor Monday, Aug. 9, to complete the repairs.

Flight controllers and station managers made the decision Monday nightafter reviewing proposed timelines, final procedures for the repairwork, and the results from a spacewalk dress rehearsal conducted inthe Neutral Buoyancy Laboratory near NASA's Johnson Space Center inHouston.

NASA Television coverage of both spacewalks will begin at 5 a.m. CDT.Wheelock and Caldwell Dyson are expected to begin the spacewalks fromthe Quest airlock at 5:55 a.m. Friday's spacewalk will be the fourthfor Wheelock and Caldwell Dyson's first.

Approximately two hours after the conclusion of each spacewalk, NASATV will broadcast a briefing from Johnson. The briefing participantswill be Mike Suffredini, International Space Station program manager;Courtenay McMillan, Expedition 24 spacewalk flight director; andDavid Beaver, Expedition 24 spacewalk officer.

Reporters may ask questions from participating NASA locations, andshould contact their preferred NASA center to confirm participation.Johnson will operate a telephone bridge for reporters with validmedia credentials issued by a NASA center. Journalists planning touse the service must contact the Johnson newsroom at 281-483-5111 nolater than 15 minutes prior to the start of a briefing. Phone bridgecapacity is limited and will be available on a first-come,first-serve basis.

Engineers and flight controllers continue to review data on thefailure, which resulted in the loss of one of two cooling loopsaboard the station. This caused a significant power down and requiredadjustments to provide the maximum redundancy possible for stationsystems. The systems are stable, and the six crew members aboard arenot in any danger.

Wheelock and Caldwell Dyson originally were scheduled to perform aspacewalk to outfit the Russian Zarya module for future robotics workand prepare the station for the installation of a new U.S. permanentmultipurpose module. However, because of the importance of restoringredundancy to the station's cooling and power systems, the two newspacewalks will be dedicated to the pump module replacement.

If this were a Russian failure they would have been out the airlock the same day. They're trained for that, in Russian they call it:.

I think a better question is: what is NASA going to do when the ISS sized vehicle they want to go to Mars in has a similar issue? Spend a few days worrying about it and calling back to Earth then go replace it with a spare and hope the spare doesn't break? Sooner or later they're going to have to break their addiction with resupply and ground based mission control. I sa

I think a better question is: what is NASA going to do when the ISS sized vehicle they want to go to Mars in has a similar issue? Spend a few days worrying about it and calling back to Earth then go replace it with a spare and hope the spare doesn't break?

"Making the ISS self sufficient for that long is essentially impossible on two grounds: First, it wasn't designed to be so. Second, we lack the experience to know what level of spares and maintenance are required."

If that's not a can't do attitude I don't know what is.

Go study the Russian program someday, you'll discover what a real space program looks like. It's not "prefab everything and don't do anything in space without a 12 point plan".

"Making the ISS self sufficient for that long is essentially impossible on two grounds: First, it wasn't designed to be so. Second, we lack the experience to know what level of spares and maintenance are required."

If that's not a can't do attitude I don't know what is.

No, it's a statement of fact on par with "the sun will rise in the East tomorrow". You mistake it for a "can't do attitude" because either you lack the intelligence or the education to understand this or because you're deliberately being obtu

If somebody panics and takes off in a soyuz without the helmet for their pressure suit, and the docking port is stuffed, will they be able to get back in through an air lock? I suspect not, because the flow in those airlocks is very slow and you need to flood the lock in a minute or so. I don't think its going to work.

Also the Soviet explosive bolts leave much to be desired. You would look pretty silly with half your hatch blown off.

Well, there's one Slashdotter who didn't get it. They are not control loops, they are loops of coolant. When you take the output of a pump and connect it to the input, you create a loop. Fluid is circulated in a loop by the pump.

I would wish I spoke for everyone when I say good luck fixing the colling system. I personally hope that the spacesuit doesn't come off during the walk, because, at the rate the ISS has been going with failures, that's probably what's gonna happen.